Metachronous colonic lymphomas complicating chronic ulcerative colitis.

The gastrointestinal tract is the most common extranodal site of primary non-Hodgkin's lymphoma. Of these, 10-15% occur in the large bowel. Colonic lymphoma is a recognized complication of inflammatory bowel disease, particularly ulcerative colitis and, less commonly, Crohn's disease. We describe a unique case of two metachronous primary lymphomas of the large bowel in a patient with chronic ulcerative colitis.